Edmonton Oilers winger Josh Archibald is out indefinitely after being diagnosed with myocarditis.

Head coach Dave Tippett told reporters Archibald had tested positive for COVID-19 over the summer.

The U.S. Centers for Disease Control and Prevention released a study that found an increased rate of myocarditis, an inflammation of the heart muscle, in patients who had COVID-19.

The condition can be serious, even for a professional athlete in the prime of his career. Boston Red Sox starting pitcher Eduardo Rodriguez missed the entire 2020 MLB season after being diagnosed with the ailment.

Rodriguez told the New York Times' James Wagner he initially couldn't hold down any food and lost 20 pounds in 10 days.